CVE-2024-27778 Overview
CVE-2024-27778 is an OS command injection vulnerability in Fortinet FortiSandbox. The flaw is classified as improper neutralization of special elements used in an OS command [CWE-78]. An authenticated attacker holding at least read-only permissions can execute unauthorized commands on the underlying operating system through crafted requests.
The issue affects multiple FortiSandbox branches, including 4.4.0 through 4.4.4, 4.2.1 through 4.2.6, 4.0.0 through 4.0.4, all 3.2 and 3.1 versions, and 3.0.5 through 3.0.7. Successful exploitation compromises confidentiality, integrity, and availability of the appliance.
Critical Impact
Authenticated attackers with minimal read-only privileges can achieve arbitrary command execution on FortiSandbox appliances, enabling full compromise of the sandbox environment.
Affected Products
- Fortinet FortiSandbox 4.4.0 through 4.4.4
- Fortinet FortiSandbox 4.2.1 through 4.2.6 and 4.0.0 through 4.0.4
- Fortinet FortiSandbox 3.2 (all versions), 3.1 (all versions), and 3.0.5 through 3.0.7
Discovery Timeline
- 2025-01-14 - CVE-2024-27778 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-27778
Vulnerability Analysis
CVE-2024-27778 is an OS command injection flaw [CWE-78] in the FortiSandbox management interface. The product fails to properly neutralize special elements passed through user-controlled request parameters before they reach an operating system shell. An attacker crafts a request containing shell metacharacters, and the appliance concatenates the input into a command line that gets executed by the underlying OS.
Exploitation requires network access to the management interface and authentication with any account, including one holding only read-only permissions. This low privilege bar significantly widens the attack surface, since read-only credentials are often distributed more broadly than administrative ones.
The outcome is arbitrary command execution in the context of the FortiSandbox service, providing an attacker with a foothold on a security appliance that inspects untrusted files across the network.
Root Cause
The root cause is missing or insufficient input sanitization on request parameters that are later used as arguments in OS-level command invocations. Special shell characters such as ;, |, backticks, and $() are not stripped or escaped, allowing command chaining and substitution.
Attack Vector
The attack vector is network-based against the FortiSandbox HTTPS management interface. The attacker authenticates with any valid account, then submits a crafted API or web-UI request whose parameter contains injected shell syntax. The malicious payload is interpreted by the shell that FortiSandbox spawns to run its intended command, resulting in execution of attacker-supplied commands.
No verified proof-of-concept code is publicly available. See the Fortinet PSIRT Advisory FG-IR-24-061 for vendor technical details.
Detection Methods for CVE-2024-27778
Indicators of Compromise
- Unexpected child processes spawned by FortiSandbox service accounts, particularly shells such as /bin/sh or /bin/bash invoking network utilities.
- Outbound connections from the FortiSandbox management interface to unfamiliar external hosts.
- HTTP/HTTPS request logs containing shell metacharacters (;, |, `, $(), &&) in parameter values sent to management endpoints.
- New or modified files in system directories on the appliance and unexpected cron entries.
Detection Strategies
- Inspect FortiSandbox audit and access logs for authenticated sessions from read-only accounts issuing requests to administrative or diagnostic endpoints.
- Alert on request payloads to FortiSandbox APIs containing common command injection patterns.
- Correlate authentication events with subsequent configuration or diagnostic API calls from the same session.
Monitoring Recommendations
- Forward FortiSandbox syslog and audit events to a central SIEM and retain them for extended review.
- Baseline normal API usage by role and alert on read-only accounts issuing write or diagnostic calls.
- Monitor egress traffic from management interfaces of security appliances, which should be minimal and predictable.
How to Mitigate CVE-2024-27778
Immediate Actions Required
- Upgrade FortiSandbox to a fixed release as listed in Fortinet PSIRT Advisory FG-IR-24-061.
- Restrict management interface access to a dedicated administrative network or jump host using firewall rules.
- Audit all FortiSandbox local and remote accounts, revoke unused credentials, and rotate any read-only account passwords.
- Enforce multi-factor authentication for administrative and read-only accounts where supported.
Patch Information
Fortinet has published fixed builds for the affected FortiSandbox branches. Refer to Fortinet PSIRT Advisory FG-IR-24-061 for the specific patched versions and upgrade guidance for each supported branch.
Workarounds
- Where immediate patching is not possible, block network access to the FortiSandbox management interface from untrusted segments.
- Disable or remove read-only accounts that are not strictly required for daily operations.
- Place the management interface behind a VPN or zero-trust network access solution to reduce exposure.
# Example: restrict FortiSandbox management access to a trusted admin subnet
# Apply on the upstream firewall protecting the appliance
iptables -A FORWARD -p tcp -d <fortisandbox_mgmt_ip> --dport 443 \
-s 10.10.50.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d <fortisandbox_mgmt_ip> --dport 443 \
-j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
